> ...at which point (including time to travel to those probes), they
> become part of the latest-generation wave. Assuming it's not less
> resource-costly to scrap or ignore 'em, in which case any "colonists"
> on said probe would be rendered obsolete by being behind the leading
> edge of colonization.

And if the conlonist are human or equivalent with their own plans,
rights (presumably) and so on? You hopefully would not casually
"obsolete" them.